The screws that get me are the ones that hold igniters on the burner tube mount and the screws that hold the gas burner heads down on the stove top. They always seem to rust on. The ignitor screws usually just strip completely out, and you have to pry them up while turning, otherwise they just spin. The stove burner screws generally just break and leave a screw shaft in the hole. I've taken to giving them a sharp rap or two before trying to remove them so that I can break 'em loose before stripping them.

When I put washers together, I use a dab of anti-sieze on the threads, to save me or someone else a headache down the road.